Solar panels, heat pumps and insulation in Dulwich Wood conservation area
In the Dulwich Wood conservation area (Southwark), external wall insulation needs planning permission, and so does an air source heat pump on a wall or roof facing the road; one at the back or side, internal and loft insulation and solar panels on a roof slope normally do not. An Article 4 direction published by Southwark covers part of this area (about 20% of it), but the published data does not say which rights it removes — check the direction before any work. The area has 13 listed buildings; on a listed building solar panels and heat pumps are not permitted development at all and need planning permission and listed building consent. 580 homes inside the boundary have an energy certificate: 35.0% are solid-wall homes with no wall insulation, 65.7% heat with a gas boiler and 63.8% are rated D–G; 6 have a heat pump. EPC register November 2026; rules as at 21 October 2026.
Data: EPC register November 2026 (latest certificate per home), conservation area boundaries 3 November 2026, permitted development rules as at 21 October 2026 · calculated 5 November 2026 · Methodology and sources
580homes with an energy certificate
35.0%solid walls, no insulation
65.7%heated by a gas boiler
6heat pumps
Article 4: An Article 4 direction published by Southwark covers part of this area (about 20% of it), but the published data does not say which rights it removes — check the direction before any work. (Great North Wood; Railway Arches; Site allocation NSP38:l The Grove Tavern, 520 Lordship Lane; The Grove Tavern; The Woodhouse)
What needs planning permission in Dulwich Wood
Work (house, not listed)
In a conservation area
Rule
Air source heat pump on a wall or roof facing the road, or nearer the road than the house
Planning permission needed
Part 14 Class G, G.1(j)
Air source heat pump at the back or side (outdoor unit up to 1.5 m³, MCS Planning Standards, one per house — two on a detached house)
No permission needed (permitted development), unless an Article 4 direction removes it — check with the council
Part 14 Class G
Solar panels on a pitched roof (up to 0.2 m proud, not above the ridge)
No permission needed (permitted development), unless an Article 4 direction removes it — check with the council
Part 14 Class A, A.2(c)
Solar panels on a wall, balcony or roof enclosure facing the road
Planning permission needed
Part 14 Class A, A.2(e)
Solar panels on a flat roof (up to 0.6 m above the roof)
Prior approval of appearance from the council, unless an Article 4 direction removes it — check with the council
Replacement windows and doors of similar appearance
No permission needed (permitted development), unless an Article 4 direction removes it — check with the council
Part 1 Class A, A.3(a)
Listed buildings: 13 in the area (grade I: 0, II*: 1). The table is for houses that are not listed: on a listed building, solar panels and air source heat pumps are not permitted development at all (they need planning permission), and any of these works needs listed building consent.
Flats: 55% of the certified homes here are flats or maisonettes. Homes in a block of flats have no householder rights for alterations; heat pumps and solar have their own, tighter rules for blocks of flats.
The homes in the area (latest certificate per home, n = 580)
Walls
Homes
Share
Solid wall (brick or stone), no insulation
203
35.0%
Cavity wall, unfilled
126
21.7%
Cavity wall, insulated (as built or unspecified)
79
13.6%
Timber frame
57
9.8%
Other or not known
51
8.8%
Cavity wall, filled
16
2.8%
Modern wall (U-value from the design)
14
2.4%
Solid wall, internal insulation
14
2.4%
Cavity wall, partly insulated
12
2.1%
Cavity wall, internal or external insulation
3
0.5%
Solid wall, insulated
3
0.5%
Solid wall, partly insulated
2
0.3%
Heating
Homes
Share
Gas boiler
381
65.7%
Electric (storage heaters, panels, boiler)
109
18.8%
Communal heating
84
14.5%
Heat pump
6
1.0%
Loft / roof insulation
Homes
Share
No insulation
82
14.1%
Under 200 mm
81
14.0%
200 mm or more
52
9.0%
Insulated (depth not recorded)
123
21.2%
Flat or other home above
228
39.3%
Other
14
2.4%
Windows
Homes
Share
Double glazed
524
90.3%
Single glazed
43
7.4%
Secondary glazing
10
1.7%
Triple glazed
3
0.5%
CDE
Energy rating: A 1 (0.2%) · B 19 (3.3%) · C 190 (32.8%) · D 250 (43.1%) · E 102 (17.6%) · F 16 (2.8%) · G 2 (0.3%). Houses and bungalows: 45% of the homes; solar panels on 0.7% of the certificates. Most common build period on the certificates: 1950-1966. Designated: 30 September 1985.
Compared with Southwark and England
Share of homes
Dulwich Wood
All 56 areas in Southwark
England
Solid walls, no insulation
35.0%
56.7%
48.7%
Gas boiler
65.7%
71.3%
66.4%
Rated D–G
63.8%
—
56.5%
Caveats
Certificates describe a home when it was assessed; 52% of these are from 2020 or later (latest 15 October 2026). “No insulation (assumed)” is the assessor's default for older walls.
The rules are England's national permitted development rules (General Permitted Development Order 2015, Schedule 2, as at 21 October 2026). They do not cover building regulations or a council's own conditions. This is not a planning decision: ask Southwark if in doubt.
Boundary: London Borough of Southwark via planning.data.gov.uk (entity 44010238, reference 24, 180.7 ha); the council's appraisal or map. Homes are placed by the coordinates of their UPRN (OS Open UPRN); addresses are not shown.